This disclosure relates in general to routing deliveries and, but not by way of limitation, to improving Anycast routing for a distributed group of points of presence (POPs).
CDNs provide enhanced delivery of content with many optimizations. One optimization is to assign a nearby POP to deliver a request such that in a network-sense the sender and receiver are close by with few hops, little latency and/or however else quality of service (QoS) is defined. Anycast can be used to allow the Internet to assign a request to a nearby POP. In some cases, the POP assigned to an end user with Anycast may not be the most favorable location to receive content. For example, a user in Phoenix could use a POP in New York in some circumstances likely providing less than optimum QoS.
Delivery of content is greatly affected by how the broader Internet is behaving in real time or near real time. There are services that provide Internet health information that is gathered and periodically made available. This can be useful to some, but does not provide recent enough information for many decisions a CDN or other large-scale user of the Internet would require to provide high levels of QoS. General trends provided by infrequent updates does not provide the timely information to make some delivery decisions.